Avalanche Forecast

Issued: Apr 7th, 2021 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Cornices.

Avalanche Canada astclair, Avalanche Canada

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Snowfall amounts are uncertain. Dial back terrain choices where you find more than 20 cm of new snow as human-triggering avalanches may be likely.

Summary

Confidence

Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

Wednesday night: Cloudy, 5-15 cm of snow, moderate southwest wind with strong gusts at ridgetop, freezing level dropping to 1400 m.

Thursday: Mainly cloudy, 5-10 cm of snow, light west wind, treeline temperatures near -5 C, freezing level rising to 1500 m and dropping to valley bottom.

Friday: Increasing cloud, moderate southwest wind, treeline temperatures near-2 C, freezing level rising to 1800 m and dropping to 1200 m.

Saturday: Cloudy, 5-15 cm of snow, light west wind, treeline temperatures near -4 C, freezing level rising to 1500 m and dropping to valley bottom.

Avalanche Summary

On Monday and Tuesday, small wet loose avalanches were observed on steep sun-exposed slopes.

Snowpack Summary

Up to 25 cm of new snow may accumulate in favored areas in the region by midday on Thursday accompanied with moderate southwest winds. The combined snow and wind will likely form a new storm slab problem reactive to human triggering. Cornices are large, looming, and capable of triggering avalanches when they fail. 

The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack. Snow line is gradually creeping up to higher elevations.

Glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to avoid slopes with glide cracks.

Terrain and Travel

  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
  • Dial back your terrain choices if you are seeing more than 20 cm of new snow.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Storm Slabs

An icon showing Storm Slabs

Forecast new snow and wind are expected for form fresh storm slabs that will likely be reactive to human triggering. This problem is expected to become more reactive as the day goes on and as the wind creates touchier conditions. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices are large and looming along many ridgelines. They are capable of triggering large avalanches when they fail.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Apr 8th, 2021 4:00PM